The invention relates to a camera tube comprising an entrance window, a photosensitive target which is arranged opposite the entrance window, an electron gun for generating an electron beam for scanning the target, and means for reducing optical cross talk in the target.
A camera tube of this kind is known, for example, from British Patent Specification No. 1,067,186. A camera tube described in this Patent Specification has an anti-halo window for reducing optical cross-talk in the target. Because the major part of the light which is reflected by the target lands outside the target after reflection from the entrance surface of the anti-halo window (due to increased lateral displacement of the light), an anti-halo window of this kind results in a substantial reduction of the optical cross talk. In many cases, particularly in camera tubes with increased redsensitivity, the effect of the anti-halo window, however, is not completely adequate.